Piston-valve.



H. S. SPRAGUE.

PISTON VALVE.

APPLIUATION r1LBD.rBB.12,19o7.

901,846. Patented oct. 20,1908.

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H. S. SPRAGUE,

PIsToN VALYB.' APPLICATION FILED FBB.12, 1907.

Patented Oct. 20, 1908.

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H. s.. SPRAGUE. PISTON VALVE.

APPLICATION FILED FEB.12,1907.

901,846. Patented Oct. 20, 1908.

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HARVEY S. SPRAGUE, OF DANA, INDIANA.

PISTON-VALVE Specification of Letters Patent.

Application led February l2, 1907.

Patented Oct. 20, 1908.

Serial No. 357,071.

To all whom it' may concern:

Be it known that I, HARVEY S. SPRAGUE, a citizen of the United States, residing at Dana, in the county of Vermilion and State of Indiana, have invented certain new and useful Improvements in Piston-Valves, of which the following is a specification.

My invention relates to improvements in steam-engine valves, more especially the slide-type. Its objects are principally to provide for the freely moving action of the valve; to readily supply and exhaust the steam by the valve-action; to allow the passage of the steam practically entirely around the valve for expediting its delivery to the valve; to readily compensate for the wear of 'the valve; to relieve excess of steam-pressure in the valve-chamber; to provide for the freely working action of the valve as relates to its stein; to facilitate the lubrication of the valve; and to-carry out these objects in a simple, ready and effective manner.

Said invention consists of certain features r instrumentalities substantially as hereinafter fully disclosed and specifically pointed out by the claims.

In the accompanying` drawings illustrating the preferred embodiment of my invention-Figure 1 is a vertical longitudinal scction thereof. Fig. 2 is a transverse section of the same. Fig. 8 is a like view upon an enlarged scale of the valve chamber casing or housing removed. Fig. 4t is a detached partially side view and partially sectional view of the valve, with its stempartly broken away. Fig. 5 is an end view of the same. Fig. 6 is an end elevation of the valve casing or housing, showing more particularly one of its relief valves. Fig. 7 is an enlarged broken detailed sectional view also disclos-v ing more especially one of the latter.

In the disclosure of my invention, I suitably mount upon each cylinder 1 of a steamengine, within the steam-chest 2, a casing or inclosure 3 forming a chamber for, and containing a cylindric or piston-form of valve 4. Said valve casing or chamber is adjusted and held in position by screw-bolts 5, inserted through the upper portion of the steam-chest 2 and binding upon said valvecasing, and by like screw-bolts 6 screwing into the ends of said casing and adapted by suitably manipulating the same to permit of bringing their heads into engagement with the opposite portions of the steam-chests, as is apparent.

The valve #l preferably cylindric in general outline as above noted, has two endenlargements or faces 5il which have inserted thereinto series of split rings or packing 6 whereby wear may be compensated as well as providing for packing purposes. The outer-end rings are extended clear to, and stand Hush with the end-walls of the valve or piston for sharply defining the wall-edges and consequently promoting the passages of the steam to the ports delivering into the engine cylinder. The wearcompensating and packing action of the rings 6 are due to their measurably resilient character and to being split, the same being severed diagonally through their transverse areas as disclosed. Said piston or valve is centrally contracted, providing thereby a circular exhaust steam passage 7 effective, according to the position of the valve, for establishing communication between either of the ports S and the exhaust-port 9, when the other port S is shut off from said exiaust-passage 7 and is taking live steam from the steamchest and delivering it into the vengine-cylinder, as well understood in this art. Said piston-valve has its stem 10 extending through a longitudinal passage therein which is somewhat greater in cross-section than said stem to permit` of the requisite working or play of the valve or the differential movement therebetween as is clearly appreciated. Said stem has a nut 11 and a washer 12 applied to its screw-tlneaded end 13, the valve 21 having in its ends countersink-like recesses 14, one recess receiving said nut and washer and the other recess receiving a washer 15 inserted upon said stem, and effective to engage that end of the valve. Said stem is also diametrically reduced to form a shoulder 16 for engagement with said washer'15 for the retention of the valve in place as against endwise displacement, and yet does not interfere with the otherwise limited movement or play of the valve upon its stem as above described.

The valve-casing 3 has formed in its walls, beyond, but communicating with the chamber receiving the valve 4, series of arcuate steam passages 16, 17 merging into ports 1S, 19 in its base corresponding with, and opposed to the live-steam supply and exhaust ports of the engine-cylinder, as shown, for receiving and permitting the delivery of the steam through said passages 16, 17 whereby said steam is caused to encompass and cushion the valve, thus providing for effectively balancing the latter and accordingly rendering it freely moving and greatly aiding .its working action, as is apparent. The sieziini-passages 16, 17, are formed in the chamber of the outer valve-casing by means of vertical transverse partitions a integral, of course, with said casing and which partitions have circular' openings b therein coinciding with the corresponding openings in the ends of said casing receiving the pistonvalve, the edges or walls of said opei'iiugs thus forming seats for said valve and whereby the steam is allowed to pass through said passages and laterally of said valve and said seats, as in effecting the balancing of said valve. Y

AIn order to relieve excess of steam-pressure in the valve-chamber, automatically operating valves 2() are suitably seated and arranged in the heads or ends of the valvecasing whose stems are supported in brackets 21 fixed to said casing and to which stems are applied springs 22 whose tension is effective to retain the valves closed except when exerted upon beyond a predetermined pressure as will be readily appreciated. These valves are each formed preferably of a disk or plate 23 covering a port in each head or end of the valve-casing, said plate or disk having projecting from one side thereof guiding arms 24 turn-stile7 like in formation and in a single casting for controlling the movement of the valve.

lt is remarked that I have produced a steam-engine valve of the balanced slide type, which is characterized for great simplicity; which is quickly responsive in action to the steam pressure; for being effectively balanced and attended with the minimum amount of friction in movement; and is applicable generally for use without any appreciable or material changes to valve or engine-cylinder while the valve is relatively inexpensive and readily accommodated to all conditions necessary for its adoption.

lt will be further noted that my invention,

may, as just stated, be employed in connection with engines as now in use without requiring any remodeling or changes of any character whatever, thus saving the expense attending the making of new patterns, casting new cylinders and chests in order to provide for the use of a balanced valve as, so far as my experience extends, is necessary in applying all other valves of like character. lt is still further observed that by means of my valve the cylinder will be relieved of all water should the engine be started with water in the cylinder, or subsequently enter the latter, the engine priming or foaming over., thus avoiding what might otherwise result in the bursting` of the cylinder', or blowing out of its heads.

I claim- 1. A slide valve comprising a casing having a valve chamber formed therein, a piston valve received therein, and the said casing having steam passages formed therein, and openings leading from the steam passages to the valve chamber for admitting steam for cushioning the valve, and spring controlled relief valves received in the heads of the casing.

2. A steam-engine slide-valve of the piston-type, comprising a casing therefor, a chest inclosing said casing, and spring-controlled relief valves arranged in the heads or ends of said casing.

3. A steam valve of the piston type, comprising a valve-casing having a disk-shaped relief-valve arranged on the end of said casing and having projecting from one side thereof guiding arms for controlling the movement of the valve, said valve having a spring arranged in connection therewith for its retention in initial position.

In testimony whereof I afiiX my signature, in presence of two witnesses.

HARVEY S. SPRALGUE.

Vitnesses CHARLES PARKER, LEONARD A. STEWART. 

